1. Field of the Invention
This invention pertains to a portable computing device. More specifically, embodiments of this invention encompass a portable computer that implements a differentiated time period after which the computer reduces power consumption.
2. Description of the Related Art
Power management is applied to reduce power consumption of computer devices such as desktops, laptops, and portable computers. In particular, portable computer devices require conservation of battery life. Power managed implementation in such devices generally provide for the computer device to change into a state or mode of low power consumption after a period of inactivity. The period of inactivity is known in the art as a xe2x80x9ctime-outxe2x80x9d period. For portable computers such as laptops, a time-out may cause the device to switch to off or into a sleep-mode where power consumption is minimized. Typically, a time-out occurs when the user does not actuate any input components, such as a touch sensitive screen or input buttons/keys.
Some computers provide for a single time-out value to be universally applied to its entire system. Other computers such as laptops and portable computers provide for constant time-out periods that are individually applied to a specific peripheral device. In such systems, one of the peripheral devices may enter a sleep-mode after a time-out period for that device passes, while other peripheral devices or the computer itself may take longer additional time before completing the timing-out. For example, many laptop computers have one time-out value for a disk drive (e.g., two minutes), and another time-out value for a display (e.g., four minutes). The disk drive often times-out a few minutes before the display.
Handheld computers, such as Zaurus(trademark) personal digital assistants manufactured by the Sharp Corp. and the Palm III(trademark) organizer manufactured by the 3Com Corp., utilize one universal time-out which can extend for several minutes. These previous systems utilize the same time-out period even when sounding a brief alarm from a sleep state, and then stay on for the full duration of the time-out even though user activity during that time-out period may not occur. As a result, the implementation of the time-out feature in previous systems is inefficient with respect to certain applications.
What is needed is an improved time-out system for portable computers and handheld computers.
Various embodiments of this invention provide for operating a portable computer with multiple time-out periods in a manner that is more efficient and effective for conserving power than previous systems. In an embodiment, the portable computer implements one or more additional time-out periods by identifying an occurrence of an event that requires the portable computer to be in the high power state to perform a specific function. An event may include a function such as sounding an alarm, although other events are also encompassed by embodiments of this invention. When an event is identified, the power state of the portable computer prior to identifying the event is recalled. The portable computer then implements a time-out period based on its previous power state.
Other embodiments of this invention provide for a portable computer that includes a processor associated with a memory, where the processor may be operated in either a high power state or a low power state. The processor may be used to identify an occurrence of an event, as described above. When an event is identified, depending on the state of the portable computer, the processor recalls the state of the portable computer from the memory, and then executes a program to implement one or more additional time-out periods. The processor then determines a duration of a time-out period based on the previous state of the portable computer.